1. Field of the Invention
This invention relates to a magnetic transducer head and more particularly to a so-called composite type magnetic transducer head in which head portion in the vicinity of the magnetic gap is formed by the ferromagnetic metal thin film or films.
2. Description of the Prior Art
With the recent tendency towards increasing the signal recording density on the magnetic tape used for VTRs (video tape recorders), so-called metal magnetic tapes in which powders of ferromagnetic metal such as Fe, Co or Ni are used as magnetic powders for the recording medium, or so-called metallized tapes in which the ferromagnetic metal material is deposited in vacuum on the base film, are used in increasing numbers. The magnetic material of the magnetic transducer head employed for signal recording and reproduction is required to have a high saturation magnetic flux density Bs in order to cope with the high coercive force Hc of the recording media described above. With the ferrite material predominantly used as the head material, the saturation magnetic flux density Bs is rather low, while the Permalloy presents a problem in that it has a lower wear resistance.
With the above described tendency towards increasing the signal recording density, it is more preferred to make use of the narrow track width of the magnetic recording medium and hence the magnetic transducer head is required to have a correspondingly narrow recording track width.
In order to meet such requirements, a composite type magnetic transducer head is known in the art in which the ferromagnetic metal thin film having high saturation flux density is applied on the non-magnetic substrate e.g. of ceramics so as to be used as the recording track portion of the magnetic tape. The magnetic transducer head however presents a high magnetic reluctance because the path of magnetic flux is formed only by the ferromagnetic metal film of a reduced film thickness so that the operating efficiency is correspondingly lowered. In addition, an extremely time consuming operation is involved in the manufacture of the magnetic transducer head because the physical vapor deposition with extremely low film-forming speed are necessarily employed for the formation of the ferromagnetic metal thin films.
A composite type magnetic transducer head is also known in the art in which the magnetic core elements are formed of ferromagnetic oxides such as ferrite and the ferromagnetic metal thin films are applied to the magnetic gap forming surface of these core elements. However, the path of magnetic flux and the metal thin film are disposed at right angles with each other and hence the reproduction output may be lowered due to the resulting eddy current loss. Also a pseudo gap is formed between the ferrite magnetic core and the metal thin film thus detracting from the operational reliability.